# name : macro check whether a variable is blank/empty
# key : macro.check.variable.blank.empty
# contributor: Shuguang Sun
# --
/* macro to test macro parameters */
/* returns 1 if the tested parameter is blank */
/* 0 otherwise, blank means all characters are,*/
/* or are macro variables that resolve to a  */
/* blank */
/* param can be up to 65,531 characters long */
/* if numeric and several 1000 digits long may*/
/* hang the session. (Windows 32 bit OS) */
/* NOT a test for a NULL (zero length string) */
/* though may work for some of those as well */

%macro ${1:isBlank}(param);
  %sysevalf(%superq(param)=,boolean)
%mend $1;